Pulverizing mill



Sept. 1, 1931 I I. F. PFEIFFER PULVERIZING MILL Filed May 31, 1929 3 SheetsSheet. l

INVENTOR Sept. 1,1931. I. F. PFEIFFER 1,821,912

PULVERIZING MILL Filed May 51, 1929 3 Sheets-Sheet. 2

I Q WK M ami-n5 5 Sheets-Sheet. 3

Filed May 51. 1929 INVENTOR Patented Sept. 1, 193i ISADORE F. PFEIFFER, OF AURORA, INDIANA PULVERIZING HILL Application filed Kay 31, 1929. Serial No. 367,170.

or when there is undue congestion in the pul-v verizing chamber without detracting from the efiicient pulverizing impact and action of the hammer device. The hammers, of varlous improved constructions providing multiple and efiiciently shaped ends, are pivotally connected to the ends of radial holder elements of the rotary device and are free to swing back from an aligned or centrifugally extended relation to the hammer holders when a massing of material prevents centrifugal force from straightening out the hammers. The radial holders and the swinging hammers move relative to the breaking and screening surfaces or lining of the pulverizing chamber insuch relation that both the mentioned elements are active in the crushing of the material. The design of the mill in combination with this combined swinging and rigid breaker device arrangement also includes various features to render the mill extremely durable and the parts easily replaceable.

It is an object of this invention to provide a rotary hammer device for a pulverizing mill employing swinging hammers pivotally connected to the ends of radial extending holders, the device being actuated relative to the material to be crushed in such wise'that both the hammers and holders are active in Another object is to provide various typesof hammers, single and multiple ended and having various'shaped heads all having a. standardized connection end for the previ-.

holders,

Another object is to provide a pivotalously mentioned pivotal attachment to the Another object is to provide a mounting of-the radially extending holders relative to the shaft which permits a rotary give tothe holders due to a slight rotary movement thereof relative to the shaft, and which also permits a slight radial springing of the hammers when these actions are induced byachoked condition of the pulverizing chamber or condition of the material.

Another object is to provide a mounting of the shaft'of the rotary device in bearings exteriorly ofthe pulverizing chamber, and placing a dust seal around'the shaft at the portions traversing the walls of the pulverizing chamber casing.

Another object relates to the construction and mounting of the breaker plates at the intake of the mill, and also to the construction and mounting of the screening and discharge grating, permitting easy removal of tlgelgrating for replacement and interchangea iity. a

Another object is to provide a door for the mill adjacent the hammer device through which access may be. had to the hammers of the mill in the event of breakage, without disturbing the-hopper connections to the mill, and also through which door the sectional grating may be removed, and to-further' provide a means for securely latching the door in sealed closed position. i

Other objects and further advantages will be more fully set forth in a description of th accompanying drawings, in which:

Figure l is a top plan View of the mill.

Figure 2 is an end elevation thereof.

Figure '3 isa sectional-view taken on line 3-'3, Figure -1,.illustrating the construction 90 and mounting of the rotary device of the mill, certain of the hammer holders and hammers being removed for the sakeof clarity.

Figure 4 is a sectional view taken on line 44, Figure 1', "showing the relation of the rotary elementrelative to the breaker plates and'screening grating of the mill. a

Figure 5'is a side elevation of one of th hammer .holderbars removed from the mill and having its .ends broken away to illus- 100 trate the pivotal connection of the hammer thereto and the swing limitation means thereof.

Figure 6 is a detail sectional view taken on line 6-6, Figure 2.

Figures 7 to 10 inclusive, are perspective views of various types of hammers for use in this mill.

Referrin to the drawings, illustrating this invention, the mill comprises in general the combination of a casing 10 having an intake or hopper opening 11, and a semicircular grinding or screening surface 12, a rotary pulverizing device 13 extending through the pulverizing chamber and having trunnions 14 journalled in bearings exteriorly of the casing, a driving pulley 15 being secured on the outer end of one trunnion and a fiy wheel 16 on the other trunnion. A series of tool holders 17 extend radially from the rotary member in longitudinally disposed rows and are secured relative to the rotary element by means of a center rod 18. A hammer 19 is pivotally secured on the end of each holder ar, these hammers being of various formations and single or multiple ended.

Describing the casing 10 in detail, it comprises a lower section 20 rectangular in shape and having flanges 21 for attachment to the floor, and flanges 22 at the top for connection of an upper section 23 and a door 43 thereto, this section 20 being open at the top and bottom. The joinder line of the upper and lower sections is the horizontal center line of the axis of the rotary element.

The lower section provides laterally extending integral bearing platforms '24 supporting split bearings 25, these bearings being traversed by the respective trunnions 14 of the rotary element 13. The rotary element 13 may be described as a hollow shaft. It is fabricated of a cylinder 26 corresponding in length to the width of the casing and a pair of trunnion members 14 having counterturned heads 27, the counter turned portion being engaged within the respective ends of the cylinder and the shanks of the trunnions extending through and beyond the bearings.

The hollow shaft 13 extends loosely throu h the walls of the casing, that is to say, t ere is no hearing at this oint. Felt rings 28 are dovetailed into the bores in the respective side walls for sealing the openin s. In order to provide against longitu inal displacement of the rotary element relative to the bearings, each trunnion is counterturned as at 29 to fit the bore of the respective bearing and counterturned a ain as at 30 to receive spacer sleeves 31. he fly wheel, in one instance, and the pulley in i the other, are secured against the spacer sleeves.

The trunnions are tubular and the center.

League 'at the inner end. This clearing of the rod from engagement toward the inner ends of the trunnions as shown in Figure 3 is for a function relating to the hammer holder and hereinafter described.

The sleeve member of the rotary element has its walls apertured or slotted to receive three longitudinally aligned diametrically disposed sets or rows of hammer holder bars 17. These bars are'dia'metrically disposed through the cylinder so as to provide radially extending portions evenly spaced apart, around the rotary element. Disks 17 (lslee Figure 4) are mounted on the rod 18in t e cylinder or hollow shaft 13 between the respective bars 17 for preventing longitudinal shifting of the bar in the slots'of the shaft. The slots are slightly greater in width than the thickness of the bars so as to allow the rotar give heretofore mentioned to take place e ciently.

The center rod 18 passes through the center portion of each bar thereby holding the bars against lateral or radial dis lacement from the rotary element. The ro a twofold function; maintainin the pulley and fly wheel on the rotary -e ement, and maintaining the bars in position. In each instance, the pairs of slots 33 in the adj aceiit cylinder wal s for receiving each bar are formed of suflicient length to permit a slight swingin of each bar on the center rod relative to t e cylinder. This construction permittin the holder bar to move relative to the cylinder is illustrated in Figure 4.

A hammer 19 is pivotally mounted on each end of each bar, these hammers swinging close to the semicircular pulverizing and screenin surface 12. This last mentioned thus has surface is mounted in the following manner:

A rectangular plate 34 is secured against the inner face of each side wall of the casing,

each plate having asemicircularcubaway portion concentric with and fitting around theinwardly extending sealing ring boss surrounding the lower half of the rotary element. A semicircular groove 35 is provided in the face of each plate concentric with the axis of rotation of t e hammers.

In the upper end of the groove on the intake side of the mill, a curved breaker plate 36 is mounted between andwithin the 1 or draw rod 18 extends throughout the length respective grooves of the plate, this plate presenting longitudinally formed sharp edges The remainder of the semicircular grooves atthe respective sides of the casing the casing andthe plates, and provide hex agon heads on the outer ends for manipulation and eccentric studs 40 on the inner ends extending into the grooves for engaging the clamping rings. Plates 40 are pivota'lly secured to the outer face of the casing, each" set in place with a grooved straight edge engaging one side of the hexagon head to prevent rotation of the particular device, and the groove providing a lug 40" which engages a groove. in the hexagon head to prevent axial displacement of the devices from the casing.

The upper section. of the casing provides the rectangular hopper opening 11 at the upper portion thereof, this opening approximately corresponding in width to the radius of the rotary pulverizing device. This opening is offset (see Figure 4) and permits the material to be only fed into the intake side of the breaking chamber toward which the hammers revolve.

The upper edges 42 of the side walls of the upper section are concentric with the axis of rotation of the swinging hammers and coincide with the inner line of the screening surface. The door 43 is provided pivotally connected to the lower section by means of a pair of hinge connections 44, this door being semi-circular to fit on the edges 42 and providing a horizontally disposed flange 45 seating on the upper flange 22 of the lower section, and vertically disposed side flanges 46 engaging on corresponding side flanges 47 of the upper section.

The door is clamped in closed position by means of its hinge connections and by means of fastening devices at the swinging end.

thereof. The hinge pins 48 passing through the lugs of the casing and the lug of the door are tapered. The small ends of the pins carry cotter pins 48 preventing displace-- ment of the pins but permitting loosening thereof in the tapered bore of the lugs, and the heads of the pins are sufficiently largeto prevent the pins from being driven through when driven into clamping position. upper fastening devices are in the nature of hinge connections but provide removable taper pins 49 connected to the frame by hating the hammers.

The i chains 50 attached to the head ends thereof. This arrangement permits the door to be swung down upon removal of the upper pins, and the pins, when set, act to seal the door. 7 The door 43 is also provided with a handle 52 for use in handling the door when the pins have been removed.

The upper margin of the hopper openng is provided with an outwardly extendmg marginal flange 53 traversable by fastening elements for securing a conduit (not shown) of some sort, to the mill. The door is provided in order that the hopper connections need not be disturbed in the even that it becomes necessary to replace any of the hammers, and also in the event that it is necessary to remove the screening plate.

The wall of the upper section toward which the hammers revolve'is provided toward its ;upper end with a lining plate 54 having diagonally disposed sharp breaking edges 54*. The lower plate 55 adjoining the circular breaker plate and continuing the surface to the plate 36 is provided with rows of conical bosses 56. These plates are secured" to the wall'of the casing by means of screws. It is thus provided that the entire surface against which the material is disposed within the mill is of an irregular changing breaking surface, the breakin surface terminating in a screening surface or discharging the pulverized material below the mill.

Various types of hammers are used in the mill, the Figures 7 to 10flinclusive, illus- In each instance the hammer is provided with a yoke portion 57 adapted to straddle the plain end of the holder, and having aligned apertures, 58 therein for receiving a pivot pin 59 traversing the end of the holder and swingingly securing the hammer to the end of the holder.

The pulverized ends of the hammers vary in form. It may be, as shown in Figures 9 and 10, a solid wedge-shaped head 60 presenting an axe edge, or a solid rectangular head 61, or, as shown in Figures 7 and 8, the head may be slotted to provide a plurality of hammer portions 62. As shown in Figure 7, the respective hammer ends are flared or widened at'the ends to provide sharp lateral edges 63. In Figure 8, the forward edges of the hammers and the outer edges thereof are shown as tapered to a point to provide splitting edges 6464. The hammers may be reversed on the holders when worn on the striking sides.

The pivot pins 59 for securing the hammers to the holders in each instance are provided with a lateral semicircular cross slot 65, this slot being aligned with a bore 66 extending adjacent and at right angles to the pivot pin bore from the outer end of the on the end surface of the holder is in close proximity to the underside of the hammer between the yoke arms thereof for the purpose of preventing swinging of the hammer relative to the holder in anti-clockwise direction. The hammers are free to swing back in the opposite direction. The engagement of the screws with the grooves in the pins prevents lateral displacement and rotation of the pins.

It will readily be seen that by this construction it is provided that both the holder and the hammer are active in the pulverizing and breaking of the material, the apparatus combining swing and rigid hammer principles. a

As shown in Figure 4, the hammers swing back upon great resistance to their passage through the material. It depends largely upon the speed and unhindered centrifugal force with which the hammer holder is rotated just how much the hammers straighten out relative to the holders. In the event that the hammer is back,'the holder is active in breaking the material. The effect of the dc vice is to swing the hammers into the material. This flexibility and give when great resistance is met, is extremely useful in preventing breakage of the hammers. There is a threefold effort made toward this end. Not only do the hammers swing relative to the holders, but the holders swing relative to the rotary element, and also the holders, due to the spaced mounting of the center rod are free to move slightly in a radial direction. This last result ensues inasmuch as the center rod is flexible and the hammer holders spring the same as necessary.

Having described my invention, I claim:

1. A device of the class described, comprising, a casing constituting a pulverizing chamber, a rotary cylinder disposed across said chamber, means for rotating said cylinder, a series of diametrically disposed holder bars extending through the walls of the cylinder within said chamber, and a center rod secured longitudinally of the cylinder and the respective holder bars for securing said bars relative to said cylinder.

2. A device of the class described, comprising, a casing constituting a pulverizing chamber, a shaft extending through the walls of said chamber, exteriorly disposed bearings for said shaft, means for sealing the openings in the walls of said chamber through which said shaft is disposed, a series of diametrically disposed hammer holder bars extending through said shaft within the chamber, and a center rod secured longitudinally in the shaft and through the respective holder bars for securing said bars relative to said cylinder.

3. A- device of the class described, comprising, a casing constituting a pulverizing chamber, a journalled cylinder extending through said chamber, means for rotating said cylinder, a series of hammer devices extending through the walls of the cylinder within the chamber, and means within the cylinder for securing the devices against radial displacement.

4. A device of the class described, comprising, a body constituting a pulverizing chamber, a rotary element extending through the walls of said chamber, means for rotating said rotary element, a series of hammer holder bars extending radially from said rotary element within the chamber, and a center rod secured longitudinally through the rotary element and through the respective holder bars for securing said bars relative to said rotary element.

5. A mill of the class described, comprising, a casing forming a crushing. chamber, a journalled tubular shaft extending through said chamber, a series of holder bars disposed radially of and through-I the walls of said tubular shaft within the casing, a center rod secured longitudinally of and within said shaft, said rod passing through each holder bar, and the openings in the tubular shaft through which said bars extend formed of greater length than the bar width permitting rotat-ive movement of said bars on said center rod relative to saidshaft.

6. A mill of the class described, comprising, a casing forming a crushing chamber, a j'ournalle'd shaft extending throu 11 said chamber, a series of holder bars isposed radially of and through slots in said shaft within the casing, the slots in the shaft through which said bars extend formed of greater length than the bar width permitting rotative movement of said bars relative to said shaft, and means for securing the holder bars against radial displacement.

7. In a device of the class described, a casing forming a chamber, a hollow shaft traversing said chamber, a series of holder bars extending radially from said shaft, hammers pivotally secured on the re-zpective outer ends of each holder bar, and a rod secured throughout the shaft and traversing the holder bars for maintaining said bars against radial displacement.

8. A device of the class described, comprising, a casing constituting a chamber for pulverizing material, a cylinder traversing said chamber and having trunnions, bearings for said trunnions, a series of diametrically disposed tool holder bars extending through the walls of said cylinder, a rod extending throughout the length of the cylinder and through the respective bores ofsaid trunnions, means for securing said rod against longitudinal displacement, said rod passing through the centers of the respective bars for securing the same against radial displacement, the bores of said trunnions tapered from a snug rod fit at the outer ends thereof to relatively large clearance diameters at the ends entering into the cylinder whereby the center rod is permitted to spring under'pressure on th holder bars.

9. A device of the class described, comprising, a casing constituting a chamber for pulverizing material, a cylinder traversing said chamber and having trunnions thereon, bearings for said trunnions, a series of tool holder bars extending radially through the walls of said cylinder, a rod extending throughout the length of the cylinder and clear of the walls thereof and through the center bores of said trunnions, means for securing said rod against longitudinal displacement, said rod passing through the respective bars for securing the same against radial displacement relative to the cylinder whereby the rod is free to spring to permit radial movement of the bars.

10. In a device of the class described, a casing forming a pulverizing chamber, a cylinder extending through said casing walls,

said cylinder having a trunnion at each end thereof, a bearing for each trunnion mounted exteriorly of said casing, a series of tool holder bars extending radially from said cylinder through apertures in the walls thereof, and a center rod passing through the cylinder and secured in the respective trunnions thereof for maintaining the holder bars in position.

11. In a rotary hammer device, a shaft, radially extending holder bars mounted on said otal movement of the hammers on the respective holders-in one direction beyond aligned relation to the holders.

15. In a hammer mill, in combination with the rotary device and easing therefor, a semicircular door concentricall disposed relative to the rotary device, said dbor hinged to said casing, taper hinge pins for said hinges, said door having apertured lugs at its upper end,

apertured lugs on said casing adjacent the lugs of said door, and removable taper pins traversing the respective bores of the lugs.

In witness whereof, 'I hereunto subscribe my name.

ISADORE F. PFEIFFER.

shaft. hammers for attachment to the ends of each holder bar, said hammers having yoke ends, pivot pins traversing the yoke arms of each hammer and the end of the respective holder bar to which it is attached, and screws engaged into the end of each holder bar, each pin thereof engaged by said screw, the head of said screw engageable. with the under surface of the hammer and offset from the pivot center preventing swinging of the hammer in one direction.

12. In a rotary hammer device, a shaft,-radially extending holder bars mounted on said shaft, hammers pivotally secured to the ends of each holder bar,' and an abutment on the end of each holder bar offset from the pivot center for preventing swinging of the hammer in one direction. I

13. A hammer mill comprising, a casing having an intake and screening discharge grating, a rotary pulverizing device disposed therein, and adoor pivotally mounted and constituting a circular section of the casing surrounding the rotary pulverizing device, said door having hinge connections at both ends and taper pins at the hinges, whereby access may be had to the hammers through the doorway without disturbing the intake or discharge connection of the mill and the having a circular groove in the sides 

